1fuse(8) System Manager's Manual fuse(8)
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6 fuse - format and options for the fuse file systems
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9 FUSE (Filesystem in Userspace) is a simple interface for userspace pro‐
10 grams to export a virtual filesystem to the Linux kernel. FUSE also
11 aims to provide a secure method for non privileged users to create and
12 mount their own filesystem implementations.
13
15 Some options regarding mount policy can be set in the file
16 /etc/fuse.conf. Currently these options are:
17 mount_max = NNN
19 Set the maximum number of FUSE mounts allowed to non-root users.
20 The default is 1000.
21 user_allow_other
23 Allow non-root users to specify the allow_other or allow_root
24 mount options (see below).
25
27 Most of the generic mount options described in mount are supported (ro,
28 rw, suid, nosuid, dev, nodev, exec, noexec, atime, noatime, sync,
29 async, dirsync). Filesystems are mounted with nodev,nosuid by default,
30 which can only be overridden by a privileged user.
31 General mount options:
33 These are FUSE specific mount options that can be specified for all
34 filesystems:
35 default_permissions
37 By default FUSE doesn't check file access permissions, the
38 filesystem is free to implement it's access policy or leave it
39 to the underlying file access mechanism (e.g. in case of network
40 filesystems). This option enables permission checking, restrict‐
41 ing access based on file mode. This is option is usually useful
42 together with the allow_other mount option.
43 allow_other
45 This option overrides the security measure restricting file
46 access to the user mounting the filesystem. So all users
47 (including root) can access the files. This option is by
48 default only allowed to root, but this restriction can be
49 removed with a configuration option described in the previous
50 section.
51 allow_root
53 This option is similar to allow_other but file access is limited
54 to the user mounting the filesystem and root. This option and
55 allow_other are mutually exclusive.
56 kernel_cache
58 This option disables flushing the cache of the file contents on
59 every open(2). This should only be enabled on filesystems,
60 where the file data is never changed externally (not through the
61 mounted FUSE filesystem). Thus it is not suitable for network
62 filesystems and other intermediate filesystems.
63 NOTE: if this option is not specified (and neither direct_io)
65 data is still cached after the open(2), so a read(2) system call
66 will not always initiate a read operation.
67 auto_cache
69 This option enables automatic flushing of the data cache on
70 open(2). The cache will only be flushed if the modification time